Zinc fortification of whole rice grain through parboiling process

The present study evaluated the effectiveness of zinc (Zn) fortification in a parboiling process for improving Zn density in parboiled-polished rice and its potential bioavailability in the human diet. Fortification of Zn in whole paddy rice grain with 50–400 mg Zn/kg paddy rice, during parboiling, increased Zn concentrations in polished-parboiled rice from 1.3 to 4.5 times those in unfortified parboiled rice. The added Zn rapidly penetrated into parboiled rice grains in the initial soaking process before saturation. There was an exponential correlation between Zn concentrations in unpolished (r = 0.63) (p < 0.01) and polished rice (r = 0.30) (p < 0.05) and soaking time. Zinc concentrations in unpolished rice were linearly correlated with Zn concentration in the polished rice (r = 0.60) (p < 0.01). Moreover, more than half of the added Zn is retained after a simulated washing process before cooking, ranging from 64–100%. In the Zn-fortified parboiled rice, 57–100% of Zn in polished rice grain was soluble in dilute acid, which was indicative of a high potential Zn bioavailability for human intake. The results suggest that parboiled rice has great potential for Zn fortification.     

Intertwined aligned carbon nanotube fiber based dye-sensitized solar cells

Metal wires suffer from corrosion in fiber-shaped dye-sensitized solar cells (DSSCs). We report herein that stable, ultrastrong, and highly flexible aligned carbon nanotube fibers can be used not only as catalytic counter electrodes but also as conductive materials to support dye-loaded TiO(2) nanoparticles in DSSCs. The power conversion efficiency of this fiber solar cell can achieve 2.94%. These solar power fibers, exhibiting power conversion efficiency independent of incident light angle and cell length, can be woven into textiles via a convenient weaving technology.     

Theoretical and experimental analysis of droplet evaporation on solid surfaces

The evaporation of sessile drops is central to a number of important processes, including printing, washing and coating. In this paper, the evaporation of water sessile droplets on hydrophobised silicon wafers and Teflon was analysed from theoretical and experimental perspectives. The contact angle, volume and base radius of the water droplets as a function of time were determined using tensiometry. The theoretical analysis showed different evaporative flux phenomena for acute and obtuse contact angles. The non-linear evolution of residual droplet volume, contact angle and base radius are solved and depend on the hydrophobicity of the solid surface and droplet dimension. Good agreement between the theoretical and experimental results was observed during pinning and depinning stages of evaporation. It was shown that the surface roughness, hydrophobicity and the contact angle hysteresis significantly influenced the evaporation of sessile drops and need to be considered when quantifying the evaporation process.     

Low-Temperature Chemical Bath Deposition of Conformal and Compact NiOX for Scalable and Efficient Perovskite Solar Modules

A scalable and low-cost deposition of high-quality charge transport layers and photoactive perovskite layers are the grand challenges for large-area and efficient perovskite solar modules and tandem cells. An inverted structure with an inorganic hole transport layer is expected for long-term stability. Among various hole transport materials, nickel oxide has been investigated for highly efficient and stable perovskite solar cells. However, the reported deposition methods are either difficult for large-scale conformal deposition or require a high vacuum process. Chemical bath deposition is supposed to realize a uniform, conformal, and scalable coating by a solution process. However, the conventional chemical bath deposition requires a high annealing temperature of over 400 °C. In this work, an amino-alcohol ligand-based controllable release and deposition of NiO_X using chemical bath deposition with a low calcining temperature of 270 °C is developed. The uniform and conformal in-situ growth precursive films can be adjusted by tuning the ligand structure. The inverted structured perovskite solar cells and large-area solar modules reached a champion PCE of 22.03% and 19.03%, respectively. This study paves an efficient, low-temperature, and scalable chemical bath deposition route for large-area NiO_X thin films for the scalable fabrication of highly efficient perovskite solar modules.     

数字图象处理技术在血液微循环领域的应用

本文首先给出了血液微循环图片的数学模型,推导并应用了顺序统计滤波器,收到了既滤出噪声又保持血管边缘的较理想的效果.对已滤波的图象综合应用边缘跟踪、综合检测、图象二值化、彩色增强等图象处理方法,获得了清晰的毛细血管的彩色和黑白图象,并用计算机自动地测出了人体甲皱毛细血管任意截面处的上、下管径,管距,管长以及动、静脉宽度之比诸参数.为了精确地测量血流速,我们提出了一种适用于此类图象的相关测速模型,对血流的平均速度、瞬时速度以及速度面分布进行了实际测试.收到了满意的效果.     

“微机原理及接口技术”课程多媒体课件的设计

在教学领域,多媒体技术越来越显示出其优越性。应用和推广多媒体技术,改进了教师的教学方法和教学手段,对于提高教学质量具有重要作用。本文基于现代教学的需要,利用DreamweaverMX、Photoshop、Flash等多媒体和网页设计软件制作了“微机原理及接口技术”教学课件,并对制作过程中遇到的问题及其解决方法进行了探讨。     

海上风电机雷达回波及其微多普勒特征

精确模拟海上风电机雷达回波并提取其微多普勒特征,是解决海上风电场对邻近雷达台站无源干扰的关键问题。由于现有算法将风电机所处的海面背景直接以平面良导体等效而过于简单,且传统的等间距散射点模型无法表征风电机叶片的三维异形曲面特征。为此,在回波求解时引入粗糙海面前向复反射系数,同时结合风电机的三维散射点等效模型,提出了基于时域回波电场的海上风电机雷达回波数值模拟算法。根据矩量法中RWG函数离散电场方程的思想,建立风电机三维散射点等效模型。考虑到电磁波作用在海面时的畸变效应,利用粗糙海面前向复反射系数推导出了时域回波电场求解公式,并获取了海上风电机雷达回波的模拟结果。最后,将风电机海面背景下的回波微多普勒特征与自由空间下的进行对比,证明海面背景不可忽略。进一步采用控制单一变量的方法分析了微多普勒频移的海况响应特性,即浪高的均方根与多普勒频移呈负相关。这也为后续海上风电机回波的识别与滤除提供理论参考。     

Multiflash stereopsis: depth-edge-preserving stereo with small baseline illumination

Traditional stereo matching algorithms are limited in their ability to produce accurate results near depth discontinuities, due to partial occlusions and violation of smoothness constraints. In this paper, we use small baseline multi-flash illumination to produce a rich set of feature maps that enable acquisition of discontinuity preserving point correspondences. First, from a single multi-flash camera, we formulate a qualitative depth map using a gradient domain method that encodes object relative distances. Then, in a multiview setup, we exploit shadows created by light sources to compute an occlusion map. Finally, we demonstrate the usefulness of these feature maps by incorporating them into two different dense stereo correspondence algorithms, the first based on local search and the second based on belief propagation. Experimental results show that our enhanced stereo algorithms are able to extract high quality, discontinuity preserving correspondence maps from scenes that are extremely challenging for conventional stereo methods. We also demonstrate that small baseline illumination can be useful to handle specular reflections in stereo imagery. Different from most existing active illumination techniques, our method is simple, inexpensive, compact, and requires no calibration of light sources.     

Study on gas-liquid flow characteristics in stirred tank with dual-impeller based on CFD-PBM coupled model

Study on gas-liquid flow in stirred tank with two combinations of dual-impeller (six-bent-bladed turbine(6BT)+six-inclined-blade down-pumping turbine (6ITD),the six-bent-bladed turbine (6BT)+six-inclined-blade up-pumping turbine (6ITU)) was conducted using computational fluid dynamics (CFD) and popula-tion balance model (PBM) (CFD-PBM) coupled model.The local bubble size was captured by particle image velocimetry (PIV) measurement.The gas holdup,bubble size distribution and gas-liquid interfacial area were explored at different conditions through numerical simulation.The results showed that the 4 mm bubbles accounted for the largest proportion of 33％ at the gas flow rates Q =0.76 m3·h-1 and 22％ at Q =1.52 m3·h-1 for combined impeller of 6BT + 6ITU,while the bubbles of 4.7 mm and 5.5 mm were the largest proportion for 6BT + 6ITD combination,i.e.25％ at Q =0.76 m3·h-1 and 22％ at Q =1.52 m3·h-1,respectively,which indicated that 6BT + 6ITU could reduce bubble size effectively and promote gas dispersion.In addition,the gas holdup around impellers was increased obviously with the speed compared with gas flow rate.So it was concluded that 6ITU impeller could be more conductive to the bubble dispersion with more uniform bubble size,which embodied the advantages of 6BT + 6ITU combination in gas-liquid mixing.     

尿素合成塔塔板技术改造总结

对传统的普通平筛板塔板进行改造,采用高效波形塔板,加强了塔内的传热与传质,利用原合成塔下部空间,增加了塔板数目,使物料在全塔的停留时间分布更理想,反应更充分,提高了合成塔的生产效率.